Bioliquids in the wood-pulp industry

TÜV SÜD certified bioliquid sustainability at six large paper-pulp plants in Germany.

(February 2011)

'Waste liquor' is a by-product in paper-pulp production. Industrial heating stations use this by-product to generate both heat and electricity. Pulp plants which feed surplus power back into the national grid are remunerated under Germany's Renewable Energy Sources Act (Erneuerbare-Energien-Gesetz, EEG). Since January 2011, EEG payments for bioliquids used for electricity production have been subject to certification in accordance with Germany's biomass electricity sustainability ordinance (BioSt-NachV). TÜV SÜD Industrie Service provided certification of a number of sites, including three plants of Sappi Fine Paper Europe – the leading European producer of coated fine paper.

"In contrast to the certification of conventional biofuels such as palm oil and rapeseed oil, we had no previous experience with the certification of waste liquor from paper-pulp production. Given this, we had to align the certification process to the provisions of the standard", says Igor Dormuth, Project Manager Biofuel Certification at TÜV SÜD Industrie Service. "To do so, we analysed the existing potential for CO2 savings and verified whether sustainability criteria had been fulfilled throughout the entire process." In addition to assessment of the production processes and the requirements defined by management, certification also covered verification of mass balance, traceability and the CO2 emissions caused.

CO2 savings of over 90 per cent

At least 90 per cent of carbon emissions can be saved by using the waste liquor from paper-pulp production instead of fossil fuels for generating electric power. As waste liquor is considered a by-product of paper-pulp production under the BioSt-NachV and its production is emission-free, it offers an ideal carbon footprint. The waste liquor consists essentially of lignin, a substance derived from plant fibres which is left after extraction of the cellulose material. The use of fossil fuels is kept to a minimum.

"Sustainability certification by TÜV SÜD enables us to demonstrate our pioneer status in the low-carbon production of premium-quality fine papers", says Burkhard Sauer, Head of Energy Management, Sappi Stockstadt GmbH. "Using waste liquor as a bioliquid in climate-friendly combined heat and power (CHP) stations, we produce electricity from renewable sources and simultaneously use the produced heat in our paper-pulp production process". With the certification of the Alfeld, Ehingen and Stockstadt sites, all Sappi's German production facilities now have the sustainability certification required for feeding electricity into the grid.